It is possible that acute labyrinthine hydrops characteristic of Meniere disorder is related to hyperparasympathetic tone analogous to that observed in rhinorrhea or nasal congestion. This new hypothesis is supported by anatomical, clinical, and surgical arguments.
Anatomically, the ear is supplied by a parasympathetic pathway from the acousticofacial anastomoses of Wrisberg intermediate nerve and the vestibular nerve. These anastomoses are of great importance and appear at a very early stage of embryonal development, much earlier than other parts of the parasympathetic component of the facial nerve. Surgically, vestibular neurectomy via the middle fossa route conserves the anatomy of the inner ear. Together with the vestibular nerve, the acousticofacial anastomoses are removed. This operation results in an improvement of hearing that is far from negligible.
Claude-Henri Chouard. Acousticofacial Anastomoses in Meniere Disorder. Arch Otolaryngol. 1975;101(5):296–300. doi:10.1001/archotol.1975.00780340028006